ANAHEIM -- The Angels' bullpen has been working hard in the second half, and there's no let-up in sight.

The month of September may be even more taxing.

"It's all hands on deck," veteran reliever Jason Grilli said. "You can pace yourself from April to August. Once September hits, redline it, man. Put the gas pedal to the floor, go as hard as you can and don't look back."

That's the mentality the Angels' bullpen has to take on, because Garrett Richards won't be back this season, no starting pitcher is expected to be added to fill his rotation spot and manager Mike Scioscia will have to patch together nine innings every time a fifth starter is needed.

Since the All-Star break, Angels relievers easily lead the Majors in innings with 152 1/3 heading into Sunday's series finale (8 1/3 innings ahead of the Cubs). The Angels will get some much-needed depth starting Tuesday -- their first game after rosters expand for September -- with relievers like Michael Kohn, Vinnie Pestano and Cam Bedrosian expected to be added, but that won't change who Scioscia's go-to guys are on the back end.

Kevin Jepsen, who has primarily been pitching the seventh inning, is two appearances shy of his career high (68, in 2010). Setup man Joe Smith is 5 1/3 innings away from his career high (70 2/3 innings, in 2011). And much-relied-upon rookie Mike Morin will be pitching into September for the first time, already surpassing his career high in appearances.

"We look at ourselves as a unit, as a team within a team and we're all just trying to pitch our inning," said closer Huston Street, who appeared in a fourth straight game for the first time since 2010 on Saturday. "As you can see, in this type of baseball, every pitch, every inning matters."

But that workload, coupled with the fact that the Angels will finish the season playing 43 games in 45 days and that it'll take an assortment of relievers to make it past each of Richards' starts, is a troubling sign for the bullpen.

In Grilli's mind, honesty is key.

"We just all have to be smart," he said. "We all know how we feel; we have to communicate. That's a big part of it.

"It's self-evaluation, more than us being overused. There's self-accountability. There's also the hope that they understand what we're being asked to do, and if they're calling upon us, they know that we may need a day. They'll tell us."